// Tencent is pleased to support the open source community by making TNN available.
//
// Copyright (C) 2020 THL A29 Limited, a Tencent company. All rights reserved.
//
// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// https://opensource.org/licenses/BSD-3-Clause
//
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.

#ifndef TNN_EXAMPLES_UTILS_LOW_PASS_FILTER_H_
#define TNN_EXAMPLES_UTILS_LOW_PASS_FILTER_H_

#include "tnn/core/macro.h"

namespace TNN_NS {

class LowPassFilter {
public:
    explicit LowPassFilter(float alpha);
    
    float Apply(float value);
    
    float ApplyWithAlpha(float value, float alpha);
    
    bool HasLastRawValue();
    
    float LastRawValue();
    
    float LastValue();
    
private:
    void SetAlpha(float alpha);
    
    float raw_value_;
    float alpha_;
    float stored_value_;
    bool initialized_;
};

}

#endif // TNN_EXAMPLES_UTILS_LOW_PASS_FILTER_H_
